Method and apparatus for cleaning a textile creel and winding apparatus

ABSTRACT

An apparatus and method for removing waste material, such as lint and the like, from textile apparatus such as a yarn package supporting creel and a beam winding means spaced from the creel, which waste material is generated by the unwinding of a plurality of ends of yarn from packages in the creel, advancing of the yarn to the winding apparatus and rewinding of the yarn into a composite package and is normally moved toward the winding apparatus by the advancement of yarn, and wherein air is induced to flow about the textile apparatus and through a waste material collecting means with the air being directed to pass through the creel toward the winding means to impart additional impetus to the waste material being moved by advancement of the yarn and thereby ensure continued conveyance of waste material to the collecting means.

[ June 6, 1972 United States Patent Culpepper, Jr.

n G a d a m P m Mr, m m w d S mS on e a 4 9 an N 3 mm P w T d 6 mm 5 0 2 nM PA [54] METHOD AND APPARATUS FOR CLEANING A TEXTILE CREEL AND WINDING APPARATUS [72] inventor: Clifford Culpepper, Jr., 1401 Femcliff Road, Charlotte, NC. 2821 1 Jan. 2, 1970 Filed: An apparatus and method for removing waste material, such [21] APPL as lint and the like, from textile apparatus such as a yarn package supporting creel and a beam winding means spaced from the creel which waste material is generated by the un- [52] US. Cl...................................28/55.3, 28/725, 15/301,

winding of a plurality of ends of yarn from packages in the creel, advancing of the yarn to the winding apparatus and rewinding of the yarn into a composite package and is normally moved toward the winding apparatus by the advancement of yarn, and wherein air is induced to flow about the textile apparatus and through a waste material collecting means with the air being directed to pass through the creel toward the winding means to impart additional impetus to the waste material being moved by advancement of the yarn and thereby ensure continued conveyance of waste material to the collecting means.

15/306, 242/l31.1 7/00, B65h 49/00 .28/55.3, 22, 72.5; 242/131,

References Cited UNITED STATES PATENTS 2,758,041 Denning....... ..........15/345 X FOREIGN PATENTS OR APPLICATIONS ....2s/55.3 16 Claims, 4 Drawing Figures 1,073,973 1/1960 Germany.....

PATENTEDJun 6 I972 SHEET 10F 2 nwsmon: CUFFORD CULPE PPERJR,

ATTORNEYS METHOD AND APPARATUS FOR CLEANING A TEXTILE CREEL AND WINDING APPARATUS This invention relates to a method and apparatus for cleaning textile equipment and, more specifically, to a method and apparatus of cleaning a textile beam forming apparatus including a creel and a beam winder.

While consolidated package forming operations, such as beaming or beam winding, wherein a plurality of ends of yarn are drawn from packages supported by a creel along a predetermined path of travel to a winding means at which the ends are together rewound into a consolidated package, results in the generation of waste material such as lint and the like due to the handling of textile strand material, no satisfactory means has been available heretofore for collecting and disposing of such waste material. Attempts to adapt fans and similar blowing equipment to removal of lint and the like from a creel and spaced winding means arrangement by blowing the waste material to the mill room floor for collection by sweeping have encountered difiiculty due to the relatively high velocity streams of air produced by the blowing equipment adversely affecting the operation being performed by the creel and winding apparatus. Consequently, such fans and similar blowing equipment have not overcome the dangers that waste material will cause undesirable slubs or neps in the rewound textile strands.

In the absence of satisfactory cleaning for textile apparatus of the type described immediately above, installation of equipment to control temperature and humidity within a textile mill room enclosing such apparatus has not been widely successful. Thus, working conditions in such a room generally are unattractive as compared to other areas of a textile mill operation, and the absence of a properly conditioned atmosphere around the textile strands adversely affects the operations of the textile apparatus.

With the above discussion in mind, it is an object of the resent invention to provide an apparatus and method of cleaning waste material such as lint and the like from a textile apparatus of the type discussed above wherein conveyance of waste material results from the imparting of additional impetus to the waste material, which is normally moved by yam advancement, by a relatively low velocity flowing current of air from the creel toward the winding apparatus. The relatively low velocity of air movement successfully employed in this cleaning apparatus and method is such that the beam winding operation continues substantially undisturbed, even though the waste material such as lint and the like is removed from the textile apparatus and collected from the textile mill room enclosing the apparatus. Such control over the removal and collection of waste material facilitates installation of air conditioning equipment for such a textile mill room.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is a perspective view, partially broken away and partially in section, of a textile mill room enclosing textile apparatus including a yam package supporting creel and a winding apparatus spaced from the creel and illustrating an installation of the present invention;

FIG. 2 is a plan view of the textile mill room and apparatus of FIG. I;

FIG. 3 is an elevation view, partially in section and partially schematic, through the textile mill room of FIGS. 1 and 2; and

FIG. 4 is an enlarged plan view, in partial section, through a portion of the cleaning apparatus of the present invention, taken generally along the lines 44 in FIG. 3.

Referring now more particularly to the drawings, the method and apparatus of the present invention will first be discussed with reference to the removal of waste material generated by textile apparatus enclosed within a mill room defined by a floor 10, side walls 11 and 12 (FIGS. 1 and 2), end walls 14 and 15, and a roof 16. The textile mill room, as so defined, encloses textile apparatus including first and second yarn package supporting creels, generally indicated at and 21 respectively, and first and second beam winding means, respectively indicated generally at 22 and 23. Each of the creels 20 and 21 comprises an arrangement of supporting frames having means thereon adapted to receive and support a large number of yarn packages. Such creel structures generally are known to persons skilled in textile manufacturing processes, are described in previously granted patents directed particularly thereto, and may vary among the different forms and structures known to the prior art without affecting the substance or scope of the present invention. It is of importance in the present invention that a plurality of ends of yarn or strands of textile material are supplied from each creel 20 and 21 to the corresponding beam winding means 22 and 23. 1

In similarity to the creels, the beam winding means 22 and 23 is a type of means generally well known to persons working in textile manufacturing, shown in various previously granted patents, and variable within the scope of prior art disclosures without affecting the substance of the present invention. It is typical of an installation of textile apparatus to which the present invention relates that rotation of a package core or beam, usually constructed to have a right circular cylindrical center portion and beam flanges or heads'at opposite ends thereof, rewinds a plurality of ends of yarn from packages supported in the creel, advances the ends of yarn from the creel to the beam, and rewinds the ends of yarn about the beam to form a consolidated package subsequently used in another textile manufacturing process. In such an operation, the unwinding, advancing and rewinding of the textile strands generates lint or loose textile fibers. Normally, this waste material has movement imparted thereto by the advancement of the textile strands from the creel toward the beam winding means so that the waste material normally moves toward the beam winding means from the creel.

Recognizing that directing high velocity currents of air into engagement with the textile strands moving from the creels to the beam winding means in an effort to dislodge lint therefrom might disrupt the winding operation, the present invention achieves cleaning of the apparatus and the textile mill room enclosing the apparatus by a novel cooperation between a relatively low velocity current of air and the yarn movement which is characteristic of the winding operation. More particularly, air is induced to flow, in accordance with the present invention, in a current directed to pass through the creels 20 and 21 from a location behind the creels therethrough and toward the winding means 22 and 23 (as shown by arrows in the drawings). As a result, additional impetus is imparted to the normally moving waste material by the relatively low velocity flowing current of air to ensure conveyance of the waste material to a collection point and hence cleaning of the same from the apparatus and the room. In accordance with the present invention, the velocity of air flow through the creel preferably is below that required to bear and convey waste material by air movement alone.

In order to collect and remove waste material thus conveyed, the induced current preferably is directed through a waste material collecting means, preferably in the form of a.

filter such as is defined by accordian or pleated folds of a nonwoven fibrous bat 26 (FIGS. 1, 3 and 4). Thus, waste material conveyed by the combined effect of yarn advancement and air flow through the creel is directed and trapped by the extended surface area of the bat 26. Preferably and as shown in the drawings herein, the bat 26 is supported by and adjacent a housing structure 28, positioned medially between two beam winding apparatus 22 and 23. It is to be noted that the open cross-sectional area of the filter defined by the bat 26 and the housing 28 is less than the cross-sectional area of the textile mill room at the point where the air flow is passing through the creels 20 and 21. As a result of the difference in cross-sectional areas, the velocity of air flow is increased adjacent the winding apparatus 22 and 23, to thereby accelerate the movement of waste material at this point. Such acceleration of movement assists in turning waste materials from the direction of movement of the yarn toward the housing 28 (as indicated by the turning arrows in FIGS. 1 and 2) and in air-bome conveyance of the waste materials to the exposed surface area of the filter means defined by the bat 26.

In the illustrated embodiment, the lower floor of the housing 28 is spaced a short distance above the floor of the textile mill room and is provided with flow directing openings 29 and 30. As a result of this spacing differential and the flow openings 29 and 30, a portion of the air flow within the room is directed along the room floor 10 to pass into the interior of the housing 28 through the openings 29 and 30. The diversion of a portion of the air flow to the floor level results in con veyance to the filter of waste material which otherwise would drift downward to and collect on the floor.

The interior of the housing 28 also communicates, through branching ducts 31 and 32, with a pair of suction boxes 35 and 36, each positioned immediately adjacent a corresponding one of the beam'winding apparatus 22 and 23. Each of the suction boxes 35 and 36 is provided with an elongate slot opening therein, positioned immediately below the plurality of ends of yarn as the same pass from the creels 20 and 21 to the beam winding apparatus 22 and 23. As a result, a portion of the air flow within the textile mill room is diverted to pass downwardly through the sheet of textile strands and transversely thereto, into the suction slot boxes 35 and 36. Thus, the ends of yarn are cleaned of any loose waste material immediately prior to winding of the ends of yarn onto the beam by the winding apparatus 22 and 23 to further assure avoidance of unwanted slubs or neps in the yarns.

To the end of accommodating full control over both temperature and humidity conditions within the mill room that encloses the creels and beam winding means, it is preferred that the'flow of air within the room be a recirculating flow. While it is recognized that cleaning will be accomplished by a single pass air flow, where the present disclosure is followed, such a single passage of outside air through a mill room normally is quite wasteful of energy expended in conditioning the air to maintain desired temperatures or humidity within the mill. Such waste is obviated, in the illustrated arrangement, by recirculation of the air within the room.

- The recirculating flow of air within the textile mill room illustrated and herein discussed is induced by means including a centrifugal fan rotor40 driven in rotation by suitable drive means such as an electric motor 41 and mounted in an opensided cage without any provision of a scroll or the like. The absence of a scroll results in multi-directional delivery of air from the rotor, giving a more uniform distribution to the recirculating air flow induced by the fan rotor. The inlet to the fan rotor 40 communicates with the interior of the housing 28 through an elongate suction duct 42, which duct extends from a location adjacent the winding apparatus 22 and 23 longitudinally of the textile-mill room between the creels 20 and 21 and terminates at an outlet opening spaced rearwardly of the creels 20 and 21. In operation of the apparatus in accordance with the method herein described, the rotational speed of the fan rotor 40 is so established that the air flow therethrough expressed in cubic feet per minute correlates to the effective cross-sectional area of the mill room at ithe creels 20 and 21 and the velocity of air flow through the creels is below that I required to convey air-bome waste material such as lint and the like by air movement alone.

While described herein with particular reference to a textile mill room in which the cross-sectional area is substantially uniform from one end of the room to the other, and with reference to an arrangement which places the air flow inducing means at the rear of the room and results in negative pressure within the duct 42, it is contemplated that the air flow inducing means may take the form of a fan within the housing 28; so that the duct 42 may be a positive pressure duct rather than a negative pressure duct. Further, it is contemplated that air flow-directing means may be provided, either by determining the plan of the textile mill room enclosing the apparatus or by the provision of subsidiary guide means such as partitions of sheet metal or the like, which brings about a constantly decreasing cross-sectional area as air moves through the creel to the winding apparatus. The effect of such a constantly decreasing cross-sectional area would be a constantly increasing velocity of air flow, to raise the air velocity gradually to and above that velocity at which waste material such as lint and the like becomes air bome-and entirely air conveyed without reliance on the textile strand movement due to the winding operation.

It is typical of textile mill rooms enclosing apparatus of the type herein described that an overhead material handling system is provided for transport of wound beams. In the illustrated embodiment, such a material handling system has been accommodated by placement of the housing 28 generally adjacent and between the two winding means 22 and 23. Where an alternative arrangement can be made for the air flow conduit corresponding to the duct 42 such as by placement of a duct beneath the mill room floor, it is desirable to position the housing 28 spaced from and beyond the winding means 22 and 23. When so positioned, air flow is from a point behind the creels 20 and 21 therethrough and beyond the winding means 22 and 23 before turning movement of the flow occurs.

1n the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation:

What is claimed is: 1. A method of removing waste material, such as lint and the like, from textile apparatus which unwinds a multiplicity of textile strands from packages supported by a creel, advances the textile strands to a point spaced from the creel and rewinds the textile strands into a consolidated beam package, and wherein the waste material is generated from the textile strands during such operations and is normally moved by the advancement of the textile strands from the creel toward the rewinding point; said method comprising,

directing the entirety of a flow of air from behind the creel substantially uniformly through the cross-sectional area thereof toward the rewinding point at a velocity below that required to convey air-borne waste material byair movement alone in the direction of advancement of the textile strands and in the direction of normal movement of the waste material to impart additional impetus to the waste material to ensure continued conveyance of the waste material toward the rewinding point, and

collecting the waste material conveyed to a location adjacent the rewinding point by such'movement.

2. A method according to claim 1 including increasing the velocity of air flow adjacent the rewinding point to accelerate the movement of waste material.

3. A method according to claim 2 wherein the step of increasing the velocity of air flow further includes turning the air flow from the direction of strand movement to a direction generally transverse thereto forwardly of and adjacent to the rewinding point to divert the waste material from movement toward the rewinding point.

4. A method of cleaning a textile mill room enclosing a winding apparatus which unwinds a multiplicity of textile strands from packages supported by a creel, advances the textile strands to a point spaced from the creel and rewinds the textile strands into a consolidated beam package, and wherein waste'material is generated from the textile strands during such operations and is normally moved by the advancement of the textile strands from the creel toward the rewinding point; the method comprising the steps of inducing air within the room to flow in a recirculating current through a waste material collecting means at a I predetermined volume per unit of time while directing the entirety of the current of flow to pass from behind the creel substantially uniformlythrough the'crosssectional area thereof and toward the winding apparatus at a velocity below that required to convey air-borne waste material by air movement alone, and

conveying waste material from the creel by imparting additional impetus to the waste material toward the winding apparatus for collection by the waste material collecting means at a location adjacent the rewinding point. 5. A method according to claim 4 further comprising the step of passing a portion of the flowing current of air transversely of the plurality of strands immediately adjacent the winding apparatus so that the strands are free of loose waste material as the strands are wound into a consolidated package. 6. A method according to claim 4 further comprising the step of inducing a portion of the flowing current of air to pass immediately adjacent the mill room floor so that waste material otherwise descending to the floor is swept therealong.

7. A method according to claim 4 particularly adapted to facilitate cleaning of a room enclosing a plurality of yarn package supporting creels and a corresponding plural number of beam winding apparatus and further comprising the step of dividing the recirculating current at a location behind and medially of the creels so that generally similar volumes of flow pass through each of the creels.

8. In a winding apparatus having a creel for supporting a multiplicity of packages of textile strand material and a rewinding means spaced from the creel for withdrawing a multiplicity of textile strands therefrom, advancing the strands toward the rewinding means and rewinding the textile strands into a consolidated beam package, the combination therewith of means for removing waste material such as lint and the like generated by handling of the textile strands and normally moved from the creel toward the rewinding means by the textile strand movement and comprising means for passing the entirety of a flow of air from behind the creel substantially uniformly through the cross-sectional area thereof and toward the rewinding means at a velocity below that required to convey air-bome waste material by air movement alone in the direction of yarn movement thereto and for importing additional impetus to the waste material to ensure continued conveyance thereof toward the winding apparatus, and

' waste material collection means operatively associated with said means for passing a flow of air through the creel for collecting waste material from the air flow at a location adjacent the rewinding means.

9. The combination according to claim 8 wherein said means for passing a flow of air through the creel includes fan means.

10. The combination according to claim 9 wherein said means for passing a flow of air through the creel further includes duct means having an inlet opening adjacent the winding apparatus, and an outlet opening spaced rearwardly of the creel operatively communicating with said fan means.

11. The combination according to claim 10 wherein said inlet opening is spaced forwardly and laterally of the creel for turning air flow transversely across the direction of strand movement between the creel and the winding apparatus.

12. The combination according to claim 11, wherein the cross-sectional area of said inlet opening is less than the effective cross-sectional area at which the recirculating flow of air passes through the creel for accelerating the velocity of air flow as the air flow is turned transversely across the direction of strand movement into said inlet opening and so that conveyance of waste material thereto by the air flow is facilitated.

13. Means for collecting waste material such as lint and the like from a textile mill room enclosing a yarn package supporting creel and a beam winding apparatus spaced from the creel for unwinding a multiplicity of textile strands from packages supported thereby, advancing the textile strands to a point spaced from the creel and rewinding the textile strands into a consolidated beam package; said means comprising duct means extending from a location adjacent the beam winding apparatus to a location spaced rearwardly of the creel, fan means operatively coupled to said duct means for inducing a recirculating flow of air through said duct means and said mill room, said duct means and fan means cooperating to pass the entirety of the air flow substantially uniformly through the cross-sectional area of the creel in the direction of yarn .movement to the winding apparatus and at a velocity below that at which waste material is borne by the air flow alone for imparting to the waste material impetus toward the beam winding apparatus which adds with movement imparted thereto by advancement of strands toward the winding apparatus and results in continued conveyance of waste material to the duct means, and

filter means operatively connected to said duct means for removing waste material from air flowing therethrough adjacent the beam winding apparatus.

14. Apparatus according to claim 13 wherein said duct means further comprises suction box means positioned closely adjacent the beam winding apparatus for drawing a portion of the air flow transversely through the plurality of strands immediately prior to winding of the strands into a beam.

15. Apparatus according to claim 13 wherein said duct means includes an inlet opening immediately adjacent the floor of the mill room and near the beam winding apparatus for drawing a portion of the air flow across the floor and sweeping into said duct means any waste material which descends to the floor.

16. Apparatus according to claim 13 particularly adapted for cleaning a mill room which encloses a plurality of sets of creels and associated beam winding apparatus and wherein said duct means extends generally longitudinally of the mill room medially of a pair of creels and beam winding apparatus and includes a housing positioned medially of the pair of beam winding apparatus and defining an inlet opening into which air flows for recirculation, and further wherein said filter means is disposed in said inlet opening for removing waste material from the air flow before passage thereof through said duct means. 

1. A method of removing waste material, such as lint and the like, from textile apparatus which unwinds a multiplicity of textile strands from packages supported by a creel, advances the textile strands to a point spaced from the creel and rewinds the textile strands into a consolidated beam package, and wherein the waste material is generated from the textile strands during such operations and is normally moved by the advancement of the textile strands from the creel toward the rewinding point; said method comprising, directing the entirety of a flow of air from behind the creel substantially uniformly through the cross-sectional area thereof toward the rewinding point at a velocity below that required to convey air-borne waste material by air movement alone in the direction of advancement of the textile strands and in the direction of normal movement of the waste material to impart additional impetus to the waste material to ensure continued conveyance of the waste material toward the rewinding point, and collecting the waste material conveyed to a location adjacent the rewinding point by such movement.
 2. A method according to claim 1 including increasing the velocity of air flow adjacent the rewinding point to accelerate the movement of waste material.
 3. A method according to claim 2 wherein the step of increasing the velocity of air flow further includes turning the air flow from the direction of strand movement to a direction generally transverse thereto forwardly of and adjacent to the rewinding point to divert the waste material from movement toward the rewinding point.
 4. A method of cleaning a textile mill room enclosing a winding apparatus which unwinds a multiplicity of textile strands from packages supported by a creel, advances the textile strands to a point spaced from the creel and rewinds the textile strands into a consolidated beam package, and wherein waste material is generated from the textile strands during such operations and is normally moved by the advancement of the textile strands from the creel toward the rewinding point; the method comprising the steps of inducing air within the room to flow in a recirculating current through a waste material collecting means at a predetermined volume per unit of time while directing the entirety of the current of flow to pass from behind the creel substantially uniformly through the cross-sectional area thereof and toward the winding apparatus at a velocity below that required to convey air-borne waste material by air movement alone, and conveying waste material from the creel by imparting additional impetus to the waste material toward the winding apparatus for collection by the waste material collecting means at a location adjacent the rewinding point.
 5. A method according to claim 4 further comprising the step of passing a portion of the flowing current of air transversely of the plurality of strands immediately adjacent the winding apparatus so that the strands are free of loose waste material as the strands are wound into a consolidated package.
 6. A method according to claim 4 further comprising the step of inducing a portion of the flowing current of air to pass immediately adjacent the mill room floor so that waste material otherwise descending to the floor is swept therealong.
 7. A method according to claim 4 particularly adapted to facilitate cleaning of a room enclosing a plurality of yarn package supporting creels and a corresponding plural number of beam winding apparatus and further comprising the step of dividing the recirculating current at a location behind and medially of the creels so that generally similar volumes of flow pass through each of the creels.
 8. In a winding apparatus having a creel for supporting a multiplicity of packages of textile strand material and a rewinding means spaced from the creel for withdrawing a multiplicity of textile strands therefrom, advancing the strands toward the rewinding means and rewinding the textile strands into a consolidated beam package, the combination therewith of means for removing waste material such as lint and the like generated by handling of the textile strands and normally moved from the creel toward the rewinding means by the textile strand movement and comprising means for passing the entirety of a flow of air from behind the creel substantially uniformly through the cross-sectional area thereof and toward the rewinding means at a velocity below that required to convey air-borne waste material by air movement alone in the direction of yarn movement thereto and for importing additional impetus to the waste material to ensure continued conveyance thereof toward the winding apparatus, and waste material collection means operatively associated with said means for passing a flow of air through the creel for collecting waste material from the air flow at a location adjacent the rewinding means.
 9. The combination according to claim 8 wherein said means for passing a flow of air through the creel includes fan means.
 10. The combination according to claim 9 wherein said means for passing a flow of air through the creel further includes duct means having an inlet opening adjacent the winding apparatus, and an outlet opening spaced rearwardly of the creel operatively communicating with said fan means.
 11. The combination according to claim 10 wherein said inlet opening is spaced forwardly and laterally of the creel for turning air flow transversely across the direction of strand movement between the creel and the winding apparatus.
 12. The combination according to claim 11, wherein the cross-sectional area of said inlet opening is less than the effective cross-sectional area at which the recirculating flow of air passes through the creel for accelerating the velocity of air flow as the air flow is turned transversely across the direction of strand movement into said inlet opening and so that conveyance of waste material thereto by the air flow is facilitated.
 13. Means for collecting waste material such as lint and the like from a textile mill room enclosing a yarn package supporting creel and a beam winding apparatus spaced from the creel for unwinding a multiplicity of textile strands from packages supported thereby, advancing the textile strands to a point spaced from the creel and rewinding the textile strands into a consolidated beam package; said means comprising duct means extending from a location adjacent the beam winding apparatus to a location spaced rearwardly of the creel, fan means operatively coupled to said duct means for inducing a recirculating flow of air through said duct means and said mill room, said duct means and fan means cooperating to pass the entirety of the air flow substantially uniformly through the cross-sectional area of the creel in the direction of yarn movement to the winding apparatus and at a velocity below that at which waste material is borne by the air flow alone for imparting to the waste material impetus toward the beam winding apparatus which adds with movement imparted thereto by advancement of strands toward the winding apparatus and results in continued conveyance of waste material to the duct means, and filter means operatively connected to said duct means for removing waste material from air flowing therethrough adjacent the beam winding apparatus.
 14. Apparatus according to claim 13 wherein said duct means further comprises suction box means positioned closely adjacent the beam winding apparatus for drawing a portion of the air flow transversely through the plurality of strands immediately prior to winding of the strands into a beam.
 15. Apparatus according to claim 13 wherein said duct means includes an inlet opening immediately adjacent the floor of the mill room and near the beam winding apparatus for drawing a portion of the air flow across the floor and sweeping into said duct means any waste material which descends to the floor.
 16. Apparatus according to claim 13 particularly adapted for cleaning a mill room which encloses a plurality of sets of creels and associated beam winding apparatus and wherein said duct means extends generally longitudinally of the mill room medially of a pair of creels and beam winding apparatus and incluDes a housing positioned medially of the pair of beam winding apparatus and defining an inlet opening into which air flows for recirculation, and further wherein said filter means is disposed in said inlet opening for removing waste material from the air flow before passage thereof through said duct means. 